1. Field of the Invention
This invention relates generally to a periodontal surgical instrument for the removal of diseased tissue from periodontal pockets, and specifically to an ultrasonically vibrated curette that is used in periodontal curettage to separate and remove granulation tissue from surrounding bone tissue and in between adjacent teeth.
Periodontitus is a human gum disease characterized by the formation of periodontal pockets (deep spaces) between the gum and tooth resulting in the reduction of attachment between soft tissue and the tooth (bone loss). The pockets accumulate diseased tissue, termed "granulation" tissue.
Initial periodontal therapy is the meticulous removal of granulation tissue as well as inflamed gingival tissue residing in the periodontal pocket formed by surrounding healthy bone tissue and tooth. Conventionally, in recent years, the removal of granulation tissue has been accomplished by manual curettage by a periodontist or general dentist doing periodontal therapy.
The scraping action employed in periodontal curettage that separates the diseased granulation tissue or inflamed periodontal tissues from healthy bone tissue is completely different than surgical cutting that mechanically divides tissue when cut with a sharp blade. In fact, in periodontal curettage it is important that healthy bone tissue not be cut away because preservation of as much healthy bone tissue is important for firm tooth support. Also it is important that the instrument not have square edges that would gouge or cut into the roots of adjacent teeth or get caught in softer bony tissue.
The manual scraping action of the periodontist using a curette is physically strenuous because of the physical effort required in separating the sinewy diseased and healthy tissues and the numerous, awkward manual positions of the curette necessitated by the restricted accessibility of periodontal pockets. By virtue of the numerous periodontal cavities in an average patient, periodontal curettage is also not only strenuous but time consuming, requiring stamina.
The invention described herein has been found to greatly reduce the physical effort and time required for periodontal curettage. The invention utilizes an ultrasonically vibrated curette that efficiently separates diseased granulation tissue from surrounding healthy bone tissue or in between or surrounding adjacent teeth in a periodontal cavity for expeditiously voiding a periodontal pocket without traumatizing healthy bone tissue.
2. Description of Related Art
Ultrasonic energy has been conventionally used for cleaning the hard enamel of tooth surfaces for quite some time.
Surgical tools for cutting tissue have also been employed that utilize knife blades or sharp cutting edges that are mechanically vibrated at ultrasonic frequencies. An ultrasonic cutting tool is shown in U.S. Pat. No. 2,990,616 issued Jul. 4, 1961 to Balamuth et al. Here a tool is described for the cutting of a desired hole in a tooth. Since the shape of the hole demands that it be barlike in nature, all of the described art has right angles to achieve this shape. The tools are end cutting to be used similar to a wood chisel. The design of the instrument is to cut into a homogenious material and create a certain preconceived shape. Another Balamuth tool for removing tissue is shown in U.S. Pat. No. 3,526,219 issued Sep. 1, 1970. Here the inventor describes a method for the systematic removal of superficial layers of tissue using a microchopping principle. The instrument must be moved parallel to the plane of the tissue so as to not gouge the underlying tissue. The removal of individual layers and the specific need to work the instrument parallel to the plane of the tissue make it impossible to be used where the removal of tissue from a bony cavity are concerned. A vibratory surgical instrument is disclosed in U.S. Pat. No. 2,714,890 issued to Vang on Aug. 9, 1955. Here the inventor describes a blade to be used in conjunction with ultrasonic vibration to enhance the cutting action of the blade. The purpose of the blade as described is to separate tissue with a cutting action. It would be impossible for the operator to actually remove tissue with such an instrument. Balamuth et al. discloses an ultrasonically vibrated cutting knife in U.S. Pat. No. 3,086,288 issued Apr. 23, 1963. All of these devices have as a primary objective to provide a cutting action and thus are unsuitable for periodontal surgery.